Knife crime is a major problem in several parts of Scotland

Ms Jamieson joined forces with the police to mark the start of the initiative, which for the first time will operate right across Britain.

Those with weapons have until the end of June to hand them in to police.

After that, police forces have warned they will take tough enforcement action on those carrying knives.

Ms Jamieson said those who go out with a knife after taking drink or drugs were creating an "explosive cocktail".

People who started the night as the best of friends can end up on hospital beds or mortuary slabs Cathy Jamieson Justice minister

She said on Wednesday: "It is worrying to hear young people say they carry a blade for their own protection.

"The fact is that carrying a knife makes a night out more likely to end in bloodshed, not less."

She warned of the consequences of knife crime and said: "People who started the night as the best of friends can end up on hospital beds or mortuary slabs, simply because they reached for a weapon.

"Start with a blade, throw in some drink or drugs and you create an explosive cocktail - with serious consequences for the perpetrator, their families and the whole community.

"I say to those with a knife - take this opportunity to get rid of it. Clear your conscience and help clear the streets of these deadly weapons."

'Life-saving decision'

Detective Chief Superintendent John Carnochan heads the Violence Reduction Unit, set up last year by Strathclyde Police.

He said: "The amnesty is an opportunity for people to make that potentially life-saving decision and hand in their locking knife or whatever weapon they choose to carry."

He also appealed to parents, saying: "Ask yourself the question - do you know if your son leaves home carrying a knife?"

The aim is to repeat the success of a previous amnesty

He told those who keep their weapons: "After the amnesty we will be coming after you.

"In the weeks and months ahead we will be going after the most violent individuals who carry knives and engage in violent behaviour."

During a previous knife amnesty - Operation Blade that ran in Strathclyde in 1993 - more than 4,500 weapons were handed in over four weeks.

And in the following 12 months murder rates fell by 26%, with attempted murder rates dropping by 19%.